Speaker
Description
Although there is substantial observational evidence for an
early period of exponential expansion of the Universe, known as
inflation, followed by a subsequent era of radiation domination, the
intermediate period connecting these two epochs, referred to as
reheating, remains challenging to constrain. In this talk, I will
present the primordial black hole (PBH) reheating scenario, where
ultralight black holes temporarily dominate the Universe and reheat it
via Hawking radiation from their evaporation. I will discuss the
gravitational wave (GW) spectrum induced by PBH number density
fluctuations, paying particular attention to how features of the
spectrum depend on the (so far unconstrained) equation of state of the
primordial fluid. The GW signal may enter the observational window of
several future GW detectors, such as LISA and the Einstein Telescope,
indicating that it may soon be possible to directly probe the physics
of reheating via induced GWs.
